We have dined at both and both were good. Nine Dragons was yummy, and good service, but truly wasn't any different than a chinese place back home. Unless we're desperate for a place to dine, we've "been there, done that" and likely won't eat there again.
Alfredo's is unique from your regular italian restaurant at home because of their amazing fettuchini alfredo - they created the dish (the original alfredos in italy). It's fantastic and was worth the trip; you won't find anything like that at a local italian restaurant, usually, because they all use that cream based alfredo sauce. Other than the fettuchini, we found all the other dishes tasting the same as the dishes back home.
Not sure if that helps much...? Good meals at both; we'd return to Alfredos again for the fettuchini alfredo but wouldn't bother with Nine Dragons unless desperate for something to eat =)